I have built a propane meter and am wondering how much psi you use to fill your launcher. I figured it to be 3 psi in the propane meter, that seems really low to me.
I used the plans from mfanda.net (thanks for the great website). My chamber is 4" in diameter and 3 feet long.
Thanks for any help.

Edit by Moderator (MrCrowley): Please read the topic section description before posting in that section. You posted in the showcase section which clearly states is only for finished projects, a section for where you want to show off your cannon. You need to post in the discussion section which is for...discussing.